1. Field of the Invention
This invention relates to an electrocardiographic electrode and, more particularly, to an electrocardiographic electrode comprising an electrode element to be held in close contact with the skin of a man to derive a weak current from the man's body, an expansible member engagedly locked in the electrode element member and an adhesive film, having a central opening and secured to the expansible member to be held in close contact with the skin of the man.
2. Prior Art
Electricity is generated in the living body by the activity of the heart, brain, muscles, etc.
Particularly, electrocardiographic electrodes are used for diagnosing the heart by monitoring a weak current that is induced on the skin of the living body using an external electrocardiograph.
To couple an input section of the electrocardiograph and the living body electrically, it is necessary to have electrocardiographic electrodes in close contact with the skin of the living body.
A prior art electrocardiographic electrode which is held in close contact with the skin of the living body will now be explained with reference to FIG. 4. In the Figure, reference numeral 1' designates an electrode element made of a metal. An expansible member 2' engages and is secured to electrode element 1' between upper and lower clamp members 20 and 21.
The electrode element 1' has a broad bottom portion 13' which is covered by a conductive cover member (not shown). The electrode element 1' derives an electrocardiographic signal from the skin via the conductive cover member.
Such electrode member 1' for an electrocardiographic electrode, however, is made of a metal and is thus heavy. Therefore, it is not suited for being held on the skin. In addition, electrode characteristics are unsatisfactory because of high polarization voltage.
Further, the electrode element 1' has heretofore been manufactured by silver plating. This method of manufacturing the electrode element by silver plating, however, is complicated in procedure as well as being dangerous and requiring high manufacturing cost.
Furthermore, the expansible member 2' engaged in the electrode element 1' requires two clamping members 20 and 21 for holding it in an engaged state.